Tracking single molecule dynamics in the anesthetized Drosophila brain

Abstract

Super-resolution microscopy provides valuable insight for understanding the nanoscale organization within living tissue, although this method is typically restricted to cultured or dissociated cells. Here, we develop a method to track the mobility of individual proteins in ex vivo adult Drosophila melanogaster brains, focusing on a key component of the presynaptic release machinery, syntaxin1A. We show that individual syntaxin1A dynamics can be reliably tracked within neurons in the whole fly brain, and that the mobility of syntaxin1A molecules increases following conditional neural stimulation. We then apply this preparation to the problem of general anesthesia, to address how different anesthetics might affect single molecule dynamics in intact brain synapses. We find that propofol, etomidate, and isoflurane significantly impair syntaxin1A mobility, while ketamine and sevoflurane have little effect. Resolving single molecule dynamics in intact fly brains provides a novel approach to link localized molecular effects with systems-level phenomena such as general anesthesia. Impact statementA new approach to track the mobility of individual molecules using intact fly brains reveals a common presynaptic effect for different intravenous and volatile general anesthetics.